Gantry Frame


ALLtra machines feature a gantry bridge frame traveling on a floor-mounted rack and pinion drive rail system.  The gantry, comprised of two machined end-trucks which support the main cross axis beam and deck, provides the platform for the precision shape cutting processes.  All components are of modular welded steel construction with machined mounting surfaces, and are bolted together to form a ridged machine frame.  This proven design is the most rugged and accurate for heavy duty shape cutting and high speed positioning.

The trucks, each equipped with its individual drive unit, provides the motion along the x-axis.  The double drive also prevents lagging which could occur with a slave truck that is free running or mechanically coupled by an axle.  Two steel wheels located in each truck assembly ride the machined top surface of the machine rails.  A pair of side-guide rollers at each end of the master (L.H.) drive truck straddle the rail contacting the machined sides for accurate guidance.  An air blast nozzle located at each end of the truck removes dirt loosened by the wheel and rail scrapers.

The main cross axis beam supports the cutting stations and the cross axis servo drive system.  Two rectangular bars are mounted on the beam, forming the linear ways for the cross axis carriages and support for the drive rack.  The rear deck which spans the trucks also provides a frame on which several machine components are mounted such as the relay cabinet, powertrack and the gas regulator/control unit, and in some instances, satellite equipment like the plumbing boxes used with plasma systems.

Rail System

Support for the machine and longitudinal (lengthwise) travel is accomplished on elevator type rails.  The machined surfaces of the rails provide smooth, even tracking for sure accuracy.  The floor mounted rails are supported by heavy duty leveling pads featuring forged steel clips for fastening the rail to the pad and integrated adjusters for aligning the machine rail in all directions.  The ends of each rail section are machined with a tongue and grove, providing positive rail alignment.

The pads allow for fast and easy alignment of the machine rails.  However, because the straightness of the rails determine the linear accuracy of the machine, it is imperative that the rail system be properly set up before machine installation is initiated.

Carriages

The basic machine includes a (master) carriage integrated with the cross axis drive module.  It can be used to support up to three process stations, each of a different type (i.e. Plasma and Oxy/Fuel).

Additional slave carriages may be added as required.

A stainless steel band in looped around pulleys at each end of the beam with the ends attached to the master carriage.  Three way band clamps allow each slave carriage to:  a) follow the same path as the master carriage,  b) follow a mirror image to the master carriage,  or c) remain detached from the band when the station is not used.

Servo Drive System

AC Brushless servos, with a service life many times that of convention brush type servos, are used for both axis.  The lower or rail axis utilizes two servo motors, synchronized solely by the servo drive system, freeing the CNC to process only positioning and process functions.  This allows faster positioning speeds by today's high performance plasma systems.  The measuring system in also an integral part of the AC Brushless Servo Drive System.  The drives provide encoded position information to the CNC. A major advantage of this is the elimination of separate encoders and resolvers from the system.

The servo motors are directly coupled to a high precision planetary gear reducer. The drive pinion is mounted directly to the gear reducer output shaft. The design eliminates all belts, pulleys, and associated components which results in a very low maintenance drive system. The precision gear reducer with a maximum backlash of seven arc-minute translates less than 0.002 in. backlash to the standard output pinion.

Operator Controls

The CNC is interfaced with an Operator's Console utilizing a Programmable Logic Controller (PLC) for manual process control.  The PLC offers easy modification and integration of additional stations at minimal cost.  Special functions can be programmed in the PLC to control auxiliary machines or processes.  The electronic modular design simplifies systems trouble shooting.  Should a problem arise, maintenance personnel can monitor the PLC and quickly pinpoint the problem area.  Should a PLC component require replacement, the part is often available from local suppliers and, of course, available from ALLtra Corporation.

The Operator's console includes:

Oxygen/Fuel Gas Regulator Panel

Regulation of preheat oxygen, fuel gas and cutting oxygen, is accomplished by five individual regulators.  Regulated air is supplied for air blast to rails and wheels from the air pressure regulator located next to the gas regulator system under cover.  The proper air flow is adjusted by individual needle valves for each application.

Service Requirements

Service inlets for fuel gas, oxygen, air and water are generally located on the same end of the machine as the main powertrack.  Each connector is labeled as to what service is intended.  However, as an added precaution, standard color coded hose and opposite connector threads are used for fuel gas and oxygen.  Fuel gas service uses a red hose with a notched left-hand threaded connector.  Oxygen service is by green hose with a right-hand threaded connector (un-notched).  Service is continued from the inlets to the regulator system and distributed to the individual stations via manifolds.

ALLtra Corporation
1600 Patridge Rd.       P.O. Box 370       Dewey, Oklahoma 74029
Phone:  918-534-5100      FAX:  918-534-5101
email:  alltra@alltracorp.com